Think of this as a go-to pack for all the items you need to quickly access like cell phone, food, keys, basic tools, etc. The Tank Top has two Velcro & ToughTek cinch straps and a moveable Velcro OneWrap cinch on the stem to keeping it from flopping like a fish. The burly water resistant #9 coil zipper enables easy single-handed opening without sticking. Internal foam padding provides some cushion and gives structure to the pack. The interior is equipped with a flat mesh pocket and a key hook. The Tank Top fits most bikes, however the large joint where the down tube meets the top tube on some mountain and fat bikes makes our Velcro Strap Extension necessary (available separately).